The instant invention relates to fence post drivers and more particularly, to such drivers which are mountable on a vehicle.
Several past fence post drivers have been proposed, some of which are adapted for mounting on a vehicle. Such past drivers are typically mounted on the rear of a tractor or on the side of a truck. Past drivers typically include a head which is driven downwardly against the top of a fence post thus driving it into the ground. The head may be driven by, e.g., a power take-off on a tractor, movement of a three-point tractor hitch, or movement of the bed of a dump truck.
Such past drivers suffer from several deficiencies. One problem which presents itself is that the force applied to the driving head for driving the fence post is not applied along the axis of the post itself. Thus, a moment is created about the top of the fence post which tends to induce wobbling or variation in the angle of the post with respect to the ground as it is driven. This situation also stresses the apparatus itself more so than if the force were applied along the axis of the post and, a greater amount of force is required to drive the post when not applied along the axis thereof.
Another problem encountered in the use of such past apparatus relates to structure or lack thereof for bracing and aligning the post during the driving process. Often, the driving head provides the only contact between the apparatus and the fence post. In some cases, a flat surface may be adjacent one side of the fence post as it is driven downwardly. This lack of bracing of the post during driving coupled with the moment created about the top of the head of the post creates a great deal of instability in both the post and the apparatus during the driving process, thus increasing the potential for an accident and/or a crooked fence post.
The instant invention includes a tubular member adapted to be mounted in a generally upright position on the rear of a vehicle. An inner cylindrical member is slidably received within the outer member for longitudinal coaxial movement relative thereto. The outer member includes an elongate opening for receiving a fence post therethrough. When a fence post is received within the outer member beneath the inner member, downward force applied to the inner member along its longitudinal axis drives the fence post into the ground in a stable manner and in alignment with the axis of each member.
It is an object of the instant invention to provide a fence post driver which overcomes the above-enumerated disadvantages of past drivers.
It is a more specific object of the instant invention to provide a fence post driver which applies substantially all of its downward-driving force along the axis of the fence post.
It is another specific object of the invention to provide a fence post driver which includes structure for bracing and aligning a fence post along and around a substantial part thereof during the driving process.